Cardiac valve procedure methods and devices

ABSTRACT

Devices and methods for performing intravascular procedures without cardiac bypass include embodiments of temporary filter devices, temporary valves, and prosthetic valves. The temporary filter devices have a cannula which provides access for surgical tools for effecting repair of cardiac valves. The cannula may have filters which prevent embolitic material from entering the coronary arteries and aorta. The valve devices may also have a cannula for insertion of the valve into the aorta. The valve devices expand in the aorta to occupy the entire flow path of the vessel and operate to prevent blood flow and to permit flow through the valve. The prosthetic valves include valve fixation devices which secure the prosthetic valve to the wall of the vessel. The prosthetic valves are introduced into the vascular system in a compressed state, advanced to the site of implantation, and expanded and secured to the vessel wall.

REFERENCE TO PENDING PRIOR APPLICATIONS

This application is a divisional application of a co-pending U.S. patentapplication Ser. No. 10/713,386, filed Nov. 13, 2003, by William E. Cohnet al for CARDIAC VALVE PROCEDUREby METHODS AND DEVICES, now U.S. Pat.No. 7,749,245, which is a continuation-in-part of:

(1) prior U.S. patent application Ser. No. 09,700,167, filed Nov. 11,2000 Gregory H. Lambrecht et al. for CARDIAC VALVE PROCEDURE METHODS ANDDEVICES, now U.S. Pat. No. 6,896,690;

(2) prior U.S. patent application Ser. NO. 09/896,258, filed Jun. 29,2001 by Richard B. Streeter et al. for INTRAVASCULAR FILTER WITH DEBRISENTRAPMENT MECHANISM, now U.S. Pat. No. 6,692,258;

(3) prior U.S. patent application Ser. No. 10/022,951, filed Dec. 14,2001 by Richard B. Streeter for APPARATUS AND METHOD FOR REPLACINGAORTIC VALVE, now U.S. Pat. No. 6,929,653;

(4) prior U.S. patent application Ser. No. 09/896,259, filed Jun. 29,2001 by John R. Liddicoat et al. for METHOD AND APPARATUS FOR PERFORMINGA PROCEDURE ON A CARDIAC VALVE, now U.S. Pat. No. 6,769,434l; and

(5) prior U.S. patent application Ser. No. 10/014,699, filed Oct. 26,2001 by Richard B. Streeter et al. for INTRACARDIOVASCULAR ACCESS(ICVATM) SYSTEM, now U.S. Pat. No. 6,890,330.

Patent application Ser. No. 10/713,386 filed Nov. 13, 2003 also claimedthe benefit of:

(6) prior U.S. Provisional Patent Application Ser. No. 60/425,877, filedNov. 13, 2002 by William E. Cohn for CARDIAC VALVE PROCEDURE METHODS ANDDEVICES.

The above-identified patent applications are hereby incorporated hereinby reference.

FIELD OF THE INVENTION

This invention relates to surgical procedures and devices in general,and more particularly to surgical procedures and devices relating to therepair and/or replacement of cardiac valves.

BACKGROUND

Of all valvular heart lesions, aortic stenosis carries the worstprognosis. Within one year of diagnosis, half of patients with criticalaortic stenosis have died, and by three years this figure rises to 80%.Currently, there is only one effective treatment for patients withaortic stenosis-aortic valve replacement via open heart surgery.Unfortunately, this is a substantial and invasive undertaking for thepatient.

While there have been significant advances in heart valve technologyover the last thirty years, there has been little progress in thedevelopment of safer and less invasive valve delivery systems. Aorticvalve replacement currently requires a sternotomy or thoracotomy, use ofcardiopulmonary bypass to arrest the heart and lungs, and a largeincision on the aorta. The native valve is resected through thisincision and a prosthetic valve is sutured to the inner surface of theaorta with a multitude of sutures passing into the wall of the aorta.This procedure is accompanied by a 5% mortality rate, in addition tosignificant morbidity (stroke, bleeding, myocardial infarction,respiratory insufficiency, wound infection) related to the use ofcardiopulmonary bypass and the approach to the aortic valve. Elderlypatients and those who require concomitant coronary artery bypassgrafting experience increased morbidity and mortality. All patientsrequire 4 to 6 weeks to recover from the procedure.

Less invasive approaches to aortic valve surgery have followed twopaths. In the Eighties, there was a flurry of interest in percutaneousballoon valvotomy. In this procedure, a cardiologist introducedcatheters through the femoral artery to dilate the patient's aorticvalve, thereby relieving the stenosis. Using the technology available atthat time, success was limited. The valve area was increased onlyminimally, and nearly all patients had restenosis within one year. Morerecently, surgeons have approached the aortic valve via smaller chestwall incisions. These approaches still require cardiopulmonary bypassand cardiac arrest, which entail significant morbidity and a prolongedpostoperative recovery.

A truly minimally invasive approach to the treatment of aortic valvedisease requires aortic valve replacement without cardiopulmonarybypass. Such an approach would reduce patient morbidity and mortalityand hasten recovery. Although there has been great progress in thetreatment of coronary artery disease without cardiopulmonary bypass(angioplasty/stenting and “off-pump” coronary artery bypass grafting),similar advances have not yet been realized in heart valve surgery. Withan aging population and improved access to advanced diagnostic testing,the incidence of aortic stenosis will continue to increase. Thedevelopment of a system for “off-pump” aortic valve replacement would beof tremendous benefit to this increasing patient population.

There are three significant challenges to replacing a diseased aorticvalve without cardiopulmonary bypass. The first is to remove the valvewithout causing stroke or other ischemic events that might result fromparticulate material liberated while manipulating the valve. The secondis to prevent cardiac failure during removal of the valve. The aorticvalve serves an important function even when diseased. When the valvebecomes acutely and severely incompetent during removal, the patientdevelops heart failure leading to death unless the function of the valveis taken over by another means. The third challenge is placing aprosthetic valve into the vascular system and affixing it to the wall ofthe aorta.

Temporary valves have been reported in the art, most notably by Boretos,et. al. in U.S. Pat. No. 4,056,854 and Moulopoulos in U.S. Pat. No.3,671,979. All temporary valves disclosed to date have been insertedinto a vessel, advanced to a location distant from the insertion siteand then expanded radially from the center of the vessel.

These designs have many disadvantages. First, they tend to occupy asignificant length of the vessel when deployed. During a valveprocedure, it may be advantageous to place the temporary valve in avessel between two branches leading from that vessel. It may also benecessary to insert other tools through the vessel wall between thosetwo branches. A temporary valve such as the ones disclosed in the artmay leave very little room between the branches for insertion of thesetools. The valves disclosed to date tend also to be rather flimsy andmay have difficulty supporting the fluid pressures while the valve isclosed. A more significant disadvantage of these valves is that theygenerally must be inserted into a vessel at a significant distance fromthe valve to allow adequate room for deployment. If some portions of theoperation are performed through the chest wall, insertion of such atemporary valve may require a separate incision distant from the chestcavity. This adds morbidity and complexity to the procedure. Anotherdrawback of the prior art is that valves with three or fewer leafletsrely on the perfect performance of each of those leaflets. If one of theleaflets malfunctions, the valve fails to function adequately.

Throughout this disclosure the terms proximal and distal will be used todescribe locations within the vascular anatomy. In the arterial system,proximal means toward the heart while distal means away from the heart.In the venous system, proximal means away from the heart while distalmeans toward the heart. In both the arterial and venous systems a distalpoint in a blood flowpath is downstream from a proximal point. The termsantegrade and retrograde flow are also used. In the arterial system,antegrade refers to flow away from the heart while retrograde refers toflow toward the heart. In the venous system, these terms are againreversed. Antegrade means toward the heart while retrograde means awayfrom the heart.

SUMMARY OF THE INVENTION

The present invention relates to devices and methods for providing avalve within a fluid-bearing vessel within the body of a human. Thepresent invention further relates to intravascular filters capable offiltering particulate debris flowing within a vessel. The presentinvention further relates to devices and methods for performing therepair or replacement of cardiac valves.

One aspect of the present invention involves methods and devices ofperforming aortic valve repair or replacement. In one form, the methodinvolves the steps of inserting at least a temporary valve and atemporary filter into a segment of the aorta. Following placement ofthese-devices, various procedures can be carried out on the aorticvalve. Following the procedure, the temporary valve and temporarilyfilter can be removed.

The temporary valve acts to restrict retrograde blood flow whileallowing antegrade flow. Generally, the valve allows forward orantegrade flow during the systolic phase of cardiac rhythm whileobstructing flow during the diastolic phase. The valve serves to assistor replace the function of the native aortic valve while a procedure isperformed on the native valve. The temporary valve means can be one of avariety of possible designs. The embodiments described below are merelyillustrative examples and do not serve to limit the scope of thisinvention.

The temporary valve can be placed in any suitable location within theaorta and can be inserted either directly into the aorta itself oradvanced into the aorta from a peripheral vessel such as the femoral oraxillary artery. The temporary valve is preferably inserted into thevascular system in a compressed state requiring a relatively smallinsertion hole and expands or is expanded within the aorta at a desiredsite. It can then be compressed for removal. In its expanded state, thevalve can occupy the entirety of the aorta's flow path, although this isnot a requirement of the present invention and may not be preferred incertain patients with extensive atherosclerotic disease in the aorta.The temporary valve, therefore, can, but does not need to contact thewall of the aorta and can act to obstruct all or only a portion of theaorta's flow path.

The temporary filter acts to prevent emboli that may be dislodged duringthe valve procedure from moving distal to the filter. In a preferredmethod of use, the filter is placed in the aorta proximal to thebraciolcephalic artery to prevent emboli from reaching the brain. Thefilter can be one of a variety of designs, including, but not limited toa mesh filter with a pore size smaller than the dimensions ofanticipated embolic particles. The filter can be inserted directly intothe aorta or advanced into the aorta from a peripheral artery. It ispreferably inserted in a compressed state and expands or is expanded toa larger state at a desired site within the aorta.

The temporary filter and temporary valve can be separate elements orpart of a single device. They may be affixed to various tubes, rods,wires, catheters, etc., to aid in their insertion into and removal fromthe vascular system.

Once the temporary valve and filter have been placed within the aorta,various procedures can be performed safely on the aortic valve while theheart is beating. This includes, but is not limited to, balloon aorticvalvuloplasty, or removal of the aortic valve, followed by placement ofa permanent valve prosthesis. The temporary valve, temporary filter, orboth may be designed with lumens through which various procedureinstruments can be placed. Instruments might also be passed around thesedevices or through a site in the aorta proximal to them.

Another aspect of the present invention is a method of performing aprocedure on a beating heart involving, at a minimum, inserting into theaorta, a temporary valve, as described above, removing at least someportion of the native aortic valve, and placing a permanent valveprosthesis at a site within the aorta. The temporary valve allowsremoval of the native valve while reducing the risk of heart failure dueto insufficiency of the native valve. Removal of at least some portionof the native valve can be carried out with one or a variety of toolsthat can be inserted either directly into the aorta or through aperipheral artery and advanced to the native valve. Similarly, thepermanent valve prosthesis can be inserted either directly into theaorta or advanced into the aorta from a peripheral artery. The valveprosthesis is preferably inserted in a compressed state and expands oris expanded at the desired implantation site. The implantation site ispreferably proximal to the coronary arteries, but can be at any suitablelocation in the aorta. The valve can be one of a variety of types knownin the art, but is preferably a flexible valve suitable for insertinginto an artery in a compressed state. This method can further involvethe placement of a temporary filter as described above to reduce therisk of emboli generated during manipulation of the native valve. Asdescribed above, the temporary filter can be a separate device or anintegral component of the temporary valve.

Any procedure performed using the disclosed methods can be assisted byone of a variety of visualization technologies, including, but notlimited to, fluoroscopy, angioscopy and/or epi-cardial, epi-aortic,and/or trans-esophageal echocardiography. These methodologies allowreal-time visualization of intra-aortic and intra-cardiac structures andinstruments.

In one form of the invention, there is provided a method for enablingperformance of an operation on a cardiac valve of a heart while theheart is beating, the method comprising placing a valved filter devicein a flow path of a blood vessel downstream from the cardiac valve, thedevice being operative to effect greater antegrade flow than retrogradeflow through said the vessel, and being operative to restrict thepassage of emboli while allowing blood to flow through the vessel.

In another form of the invention, there is provided a method forperforming an operation on a cardiac valve of a heart while the heart isbeating, the method comprising the steps of a) positioning a valvedfilter device in a flow path of a blood vessel downstream from thecardiac valve, the device being operative to effect greater antegradeflow than retrograde flow through the vessel, b) resecting at least aportion of the cardiac valve, and c) affixing at least one prostheticvalve at or downstream from the resected cardiac valve.

In another form of the invention, there is provided a method forenabling performance of an operation on a cardiac valve of a heart whilethe heart is beating, the method comprising placing a valved filterdevice in a flow path of a blood vessel of the cardiac valve, the devicebeing operative to effect greater antegrade flow than retrograde flowthrough the vessel, and being operative to restrict the passage ofemboli while allowing blood to flow through the vessel.

In another form of the invention, there is provided a method forperforming an operation on a cardiac valve of a heart while the heart isbeating, the method comprising the steps of a) positioning a valvedfilter device in a flow path of a blood vessel downstream from thecardiac valve, the device being operative to effect greater antegradeflow than retrograde flow through the vessel, b) resecting or disruptingat least a portion of the cardiac valve, and c) affixing at least oneprosthetic valve at, upstream or downstream from the resected cardiacvalve.

In another form of the invention, there is provided a device forperforming intravascular procedures wherein the device is adapted forplacement in a flowpath of a blood vessel, the device comprising, a) avalve means operative to allow greater antegrade flow than retrogradeflow through the vessel; and b) a filter operative to restrict passageof emboli while allowing blood flow through the vessel.

In another form of the invention, there is provided a device forperforming intravascular or intracardiac procedures wherein the deviceis adapted for placement in the flowpath of blood, the device comprisinga valve means operative to allow greater antegrade flow than retrogradeflow; and a filter operative to restrict passage of emboli whilepermitting blood flow therethrough.

In another form of the invention, there is provided a device forperforming intravascular or intracardiac procedures wherein the deviceis adapted for placement in a flowpath of a blood vessel, the devicecomprising a) a valve means operative to allow greater antegrade flowthan retrograde flow through the vessel; and b) a filter operative torestrict passage of emboli while allowing blood flow through the vessel.

In another form of the invention, there is provided a valved filterdevice for use in repair and replacement of cardiac valves, the devicecomprising an elongated tube of filter material, said tube being closedat a distal end thereof and open at a proximal end thereof; and amembrane tethered to the open end of said tube at spaced apart fixationpoints, the membrane being expandable under diastolic pressure to form agenerally parabolic cone substantially blocking flow of bloodtherethrough, and compressible under systolic pressure to form asubstantially non-flow blocking configuration to permit flow of bloodtherethrough.

Specific reference is made to procedures performed on the aortic valvein this description, however the methods and devices described hereincould be applied to other valves within the heart. The devices describedabove and in the claims below can be used as part of proceduresperformed on cardiac valves, but their use is not restricted to thislimited application.

DESCRIPTION OF THE DRAWING

For a fuller understanding of the nature and objects of the presentinvention, reference should be made to the following detaileddescription taken in connection with the accompanying drawings, inwhich:

FIGS. 1A-1F depict various phases in the deployment of an exemplaryfilter device of the present invention;

FIGS. 2A-2C depict another embodiment of a temporary filter device. Asmall balloon located about the exterior of the cannula of this deviceforces blood to flow through a filter when inflated;

FIG. 3A shows a schematic representation of an endovascular procedurecatheter of the invention, with the one-way valve and filter membrane ina retracted position;

FIG. 3B depicts the endovascular procedure catheter of FIG. 3A followingdeployment of the one-way valve and filter membrane;

FIG. 4A depicts valve and filter components of the procedure catheter ofFIG. 3A viewed along the retrograde flow path. The valve is closed onthe left portion of FIG. 4A, preventing retrograde flow, and open on theright portion of FIG. 4A, allowing antegrade flow;

FIG. 4B depicts the “valve open” (left portion) and “valve closed”(right portion) positions of the procedure catheter of FIG. 3A viewedalong an axis perpendicular to the flow path;

FIG. 5A depicts the filter membrane element of the procedure catheter ofFIG. 1A as viewed along the flow path within a vessel;

FIG. 5B depicts the procedure catheter of FIG. 3A with the one-way valveremoved;

FIG. 6 depicts an exemplary deployment system for the temporary valveand filter elements of the endovascular procedure catheter of FIG. 3A;

FIGS. 7A-7D depict exemplary elements used to aid in deployment of thetemporary valve and filter element of the endovascular procedurecatheter of FIG. 3A;

FIGS. 8A and 8B depict another embodiment of a temporary valve andfilter device of the invention. The temporary valve of the depicteddevice is a small balloon on the outside of an inner cannula. Theballoon is inflated to prevent retrograde flow and deflated to allowantegrade flow;

FIGS. 9A and 9B depict another embodiment of a temporary valve andfilter device in accordance with the invention. Flaps of materialcollapse against the expandable mesh of the temporary filter to preventretrograde flow;

FIGS. 10A and 10B depict another embodiment of a temporary valve andfilter device in accordance with the invention. Slits cut in a valvematerial located about the expandable mesh provide a path for bloodduring antegrade flow and close against the expandable mesh duringretrograde flow;

FIGS. 11A and 11B depict the device of FIGS. 2A-C with the addition of aone-way valve;

FIG. 12 depicts an exploded cross-sectional view of an alternativetemporary valve assembly in accordance with the invention. In FIG. 12,components of the valve pieces are shown in cross section except forbacking element 110 and valve 111;

FIGS. 13A, 13B, 13C, 13C′, 13D and 13D′ depict a series ofcross-sectional views of the valve assembly illustrated in FIG. 12;

FIG. 13A depicts the valve of the exemplary valve assembly of FIG. 12 ina compressed state within a delivery cannula 105;

FIG. 13B depicts the valve of FIG. 13A advanced outside of deliverycannula 105;

FIG. 13C depicts the expanded valve of FIG. 13A seen looking down thelong axis of the vessel into which it is deployed. The valve is expandedby pulling back on button 101. In FIG. 13C, the valve is open, allowingflow through flexible loop 109. This depiction represents the state ofthe valve during the systolic phase when placed in the aorta and actingto support the aortic valve;

FIG. 13C′ is the same as FIG. 13C with the valve assembly viewed along aradius/diameter of the vessel into which it is deployed. Valve leaflets111 extend away to the right (as shown) of flexible loop 109;

FIG. 13D depicts the expanded valve of FIG. 13A seen looking down thelong axis of the vessel into which it is deployed. In FIG. 13D, thevalve is in a closed position, preventing flow through flexible loop109. This depiction represents the state of the valve during thediastolic phase when placed in the aorta and acting to support theaortic valve;

FIG. 13D′ is the same as FIG. 13D with the valve assembly viewed along aradius/diameter of the vessel into which it is deployed. Valve leaflets111 are collapsed against backing 110;

FIGS. 14A-14D depict the valve end of temporary valve assembly of FIG.12 inserted into a vessel. FIG. 14A is a lateral view, showing partialdeployment into the vessel. FIG. 14B is a lateral view of the deploymentof FIG. 14A, showing a rod 106 positioning the temporary valve into thevessel. In this view, the temporary valve is beginning to unfold andexpand. FIGS. 14C and 14D show similar views with the temporary valvesomewhat more deployed;

FIG. 15 depicts a temporary valve of the invention deployed in the aortawith the valve open;

FIG. 16 depicts the temporary valve of FIG. 16 deployed in the aorta,with the valve closed;

FIGS. 17A-17E show various components of a prosthetic valve and fixationsystem in lateral views (left side) and axial views (right side);

FIG. 18 depicts a method of performing surgery on a cardiac valve usinga temporary valve and filter of the invention;

FIG. 19 depicts another method of performing surgery on a cardiac valveusing a temporary valve of the invention;

FIG. 20 depicts the methods of FIGS. 18 and 19 following removal of thecardiac valve and inner cannula;

FIG. 21 depicts deployment of an expandable prosthetic valve through theouter cannula and into the valve annulus, in accordance with theinvention;

FIG. 22 depicts an exemplary method of fixing a prosthetic valve to avessel wall during cardiac rhythm, in accordance with the invention;

FIGS. 23A and 23B depict a method for repairing a stenotic aortic valve,in accordance with the invention;

FIG. 24 depicts another method for performing surgery in a cardiac valveusing a temporary valve and filter in accordance with the invention;

FIG. 25 is a perspective view of a preferred valved filter device;

FIG. 26 is an enlarged perspective view of one end of the device of FIG.25;

FIGS. 27 and 28 are perspective views of internal skeleton elements ofthe device of FIG. 25; and

FIGS. 29-35 are enlarged perspective views of a valve portion of thedevice of FIG. 25.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The methods and devices of the present invention can be used forperforming procedures on cardiac valves without cardiac arrest orcardiopulmonary bypass. Various embodiments of the methods and devicesare described to clarify the breadth of the present invention.

Preferred Embodiments-Temporary Filter Device

One critical aspect of any intravascular procedure that potentiallyinvolves the liberation of embolic material is the prevention of strokeand other ischemic events. Below, numerous temporary filter devices aredescribed that allow the passage of procedure instruments into thevascular system while filtering blood passing through the lumen of thevessel into which the instrument is placed.

FIGS. 1A-1F depict multiple stages of deployment of an exemplarytemporary filter device 10 of the present invention. This device isparticularly useful during the manipulation and/or resection of acardiac valve.

FIG. 1A shows the three primary components of the filter device 10-outercannula 1, inner cannula 2, and expandable mesh 3. Outer cannula 1 hasan inner diameter that is greater than the outer diameter of innercannula 2. Mesh 3 is generally tubular when collapsed and at leastconical in part when expanded, and is located on the outside of innercannula 2. The apex of the conical portion of mesh 3 is movably attachedto inner cannula 2 along a length proximal (to the right) of innercannula 2's distal tip. Collapsed mesh 3 is restrained on inner cannula2 between two OD steps 4 rigidly affixed or integral to inner cannula 2.These OD steps may be greater than the generalized outer diameter ofinner cannula 2 or may mark the ends of a reduced diameter section ofinner cannula 2. The apex of mesh 3 is free to slide along and rotateabout inner cannula 2's length between the two OD steps. Expandable mesh3 may be affixed to a ring (not shown) with an inner diameter largerthan the outer diameter of cannula 2 along this length. This allows thecannula to be moved along and rotated about its long axis within atubular vessel without the expandable means and filter material movingagainst and abrading the vessel wall. This feature may act to minimizethe risk of dislodging embolic material from the vessel wall duringmanipulations required by the procedure.

To maintain its collapsed state in the embodiment of FIGS. 1A-1F, theself expanding, mesh 3 is positioned against the outer surface of innercannula 2. As shown in FIG. 1F (but not shown in FIGS. 1A-1E), a filtermaterial 71, such as woven nylon mesh with a defined pore size, may bepositioned over the mesh 3. Such a material is optional and may be usedto cover at least some portion of expanded mesh 3 and may be placed oneither the outer or inner surface of mesh 3.

The outer and inner cannulae can be constructed from any one of avariety of materials, including, but not limited to, various plastics,rubber, and metals. They can be either wholly rigid or flexible innature. They can be rigid along most of their lengths with a smallflexible region or regions that allow the cannulae to bend. There canfurther be a valve means (not shown) situated along the interior ofinner cannula 2 that prevents the flow of blood while allowing passageof instruments through inner cannula 2. Either or both of inner cannula2 and outer cannula 1 can have additional degassing ports (not shown)exterior to the vascular system to allow removal of air and other gasesfrom the interiors of the cannulae.

Expandable mesh 3 can also be made from any one of a variety ofmaterials, but is preferably constructed from elastic metal woven into atube. This tube preferably has a first diameter in an expanded state anda second, smaller diameter in a compressed state. The first diameter ispreferably similar to that of the aorta or vessel in which the filter isused. The mesh itself can act as a filter or filter material can beattached along its interior or exterior. This embodiment is merely anillustrative example. There are many other potential embodiments of afilter means that could be imagined without departing from the spirit ofthe present invention.

FIG. 1B depicts assembled filter device 10, with the distal end of theinner cannula 2 inserted into the proximal end of the outer cannula 1.

FIG. 1C depicts assembled filter device 10 with the outer cannula 1retracted proximally, exposing mesh 3 and allowing its free end toexpand against the inner wall of the vessel into which it is deployed.In this embodiment, mesh 3 expands into a conical shape, with the baseof the cone extending toward the distal end of the cannulae. Innercannula 2 has a deflected tip that bends the lumen of the cannula awayfrom the long axis of the device. This bend assists in guiding anyprocedural instrument passed through the lumen of inner cannula 2 towardthe wall of the vessel and/or the attachments of a cardiac valve to thatwall. The mobility of mesh 3 in this figure permits this bend withoutaltering the orientation of mesh 3 relative to the vessel into which itis inserted. As shown, the tip of inner cannula 2 extends beyond mesh 3.Moreover, in some embodiments, that tip is steerable under the remotecontrol of a surgeon. In that configuration, a device, such as a valveresecting device which extends out of cannula 2, may be steered toresect a desired portion of a stenotic valve, for example. The inventionmay also include a fiber optic viewing assembly extending throughcannula 2.

FIG. 1D depicts the device of FIG. 1C with inner cannula 2 rotated 180about its long axis and retracted proximally. The sliding attachment ofexpanded mesh 3 to inner cannula 2 allows this to occur without anymotion of mesh 3 relative to the vessel wall.

FIG. 1E depicts the device of FIG. 1D during removal. Outer cannula 1 isadvanced over inner cannula 2 and is about to compress expanded mesh 3and any entrapped material. The mobility of expanded mesh 3 relative toinner cannula 2 causes mesh 3 to move beyond the distal end of innercannula 2. This ensures that embolic material captured by mesh 3 willnot be trapped between mesh 3 and the exterior of inner cannula 2. Thiswould prevent passage of outer cannula 1 over mesh 3 and inner cannula2. With the mobility of mesh 3 relative to inner cannula 2, a muchgreater amount of embolic material may be trapped compared to a fixedproximal filter as described in the prior art.

FIG. 1F depicts the device of FIG. 1D with filter material 71 added tothe exterior surface of expanded mesh 3. In this embodiment, expandedmesh 3 has been shortened to just the cone portion of the prior meshes.Extending distally beyond this cone are filter extensions 70 that occupyonly a portion of the circumference of a cylinder having a diameterequal to the maximum diameter of the cone-shaped mesh 3. The extensionsare adapted to lie along the vessel wall and rest over the ostium of oneor more arteries that branch from the vessel. The extensionconfiguration of FIG. 1F is advantageous for filtering the ostia ofbranch vessels that may be located between valve commissures, such asthe coronary ostia in the aorta.

For aortic valve applications, extensions 70 are preferably from threepoints spaced around the circumference of the cone's expanded end. Thesepoints are preferably 120 degrees apart. Each extension 70 is preferablya hemi-circular leaflet with the diameter of the hemi-circle beinglocated about the circumference of the cone's base. When deployed,device 10 is oriented so that the base of the cone is expanded towardthe aortic valve. The shape of the three leaflets allows the filter tobe expanded or advanced along the wall of the aorta beyond the planecreated by the three apices of the aortic valve commissures. In thisposition, the leaflets cover and filter the left and right coronaryostia while the filter cone filters blood flowing through the aorta.

In the expanded position, the three extensions 70 can be biased againstthe wall of the aorta by expandable mesh 3, by the stiffness of thefilter material 71, or by the shape of the filter itself. Extensions 70can further be designed to exploit pressure within the vessel tocompress them against the vessel wall.

Such an expandable filter acts to filter just the branch vessels withthe conical portion of the expanded mesh left uncovered by filtermaterial 71. In such an embodiment, either the partial filter extensionscan be employed (as in FIG. 1F) or full cylindrical filters (not shown)that cover the entire circumference of the vessel wall can be employed.

FIGS. 2A, 2B, and 2C show an alternative embodiment of a filter that canbe used to filter emboli from blood flowing through a vessel. Filter 20consists of cannula 17, a valve located within the interior of thecannula (not shown), an expandable means depicted as balloon 19, and afilter depicted as mesh 18. The valve interior to cannula 17 acts toprevent the flow of blood out of the vessel through cannula 17 whileallowing the passage of instruments through the lumen of cannula 17.This valve is positioned to the right of filter 18 as viewed in FIGS. 2Aand 2B. Balloon 19 can be expanded by the injection of gas or liquidthrough port 21. Once inflated, balloon 19 obstructs the flow path ofthe vessel exterior to cannula 17. Hence, the blood must flow into theinterior of cannula 17 and exit the cannula through filter 18. In thisway, emboli are prevented from flowing past the filter. In FIG. 2B, anintravascular instrument 5 has been passed through the inner lumen ofcannula 17. As instrument 5 does not occupy the entire interior flowarea of cannula 17, blood can flow around instrument 5, into cannula 17and through filter 18. FIG. 2C is an end-on view of filter 20 andinstrument 5 from the left side as viewed in FIG. 2B. In this figure,the blood flow path is annulus 22 formed by the inner wall of thecannula 17 and the shaft of the instrument 5. Additional blood flowpaths could be provided through portions of balloon 19. Optionally,these paths additionally have a filter mesh covering the path. Filter 20can be used in a variety of intravascular procedures that would benefitfrom the filtration of blood.

Preferred Embodiment-Combined Temporary Valve Devices

In order to carry out procedures on cardiac valves withoutcardiopulmonary bypass, it is critical to support the function of thevalve during the procedure. Numerous preferred embodiments of temporaryvalves that perform this function are disclosed below. Many of thesevalves are combined with filters to further limit the risk of ischemicevents that might result from liberated embolic material.

FIGS. 3-7 depict one embodiment of such a combined valve and filterdevice. As depicted in FIGS. 3A and 3B, endovascular procedure catheter2′ is inserted into the host. It is positioned over a guide wire 800 atits desired location, for this example in the ascending aorta above thecoronary arteries and below the brachiocephalic artery. Guide wire 800and guiding catheter 700 can then be removed.

Once endovascular procedure catheter 2′ is in position, temporary oneway valve 26, the selectively permeable, filtering membrane 3 (FIGS. 4A,4B, 5A and 5B), and mounting ring 900 are deployed. Deployment comprisesthe controlled, adjustable increase in the diameter of valve 26,membrane 3′, and/or mounting ring 900 until they abut or nearly abut theinner wall of the vessel.

Temporary one-way valve mechanism 26 can be comprised of any type of oneway valve. The critical function of valve 26 is to limit the aorticinsufficiency and thus, the amount of volume overload on the heartgenerated by resecting or manipulating the diseased or damaged hostvalve. This will allow procedures to be performed on the valve andreplacement of the valve without the need for partial or completecardiac bypass or cardiopulmonary bypass.

Next, the host aortic valve is resected, removed or manipulated. If thevalve is to be replaced, the new cardiac valve is implanted. This valvecan be mounted on endovascular procedure catheter 2′ or can be deliveredthrough another port of entry or cannula. Upon completion of theprocedure, all devices are retracted and removed.

The illustrated exemplary endovascular procedure catheter 2′ is acylindrical sleeve that is made of a flexible material. It is durableand resistant to thrombogenesis.

It has several associated components:

-   -   a lumen for the passage of devices e.g. imaging devices, tissue        resecting devices, valve deployment devices, the new valve, or        any other device necessary to perform endovascular procedures on        the endovascular vessels or valves    -   a guiding catheter 700 which is tapered on the end and extends        out of the working port of the endovascular procedure catheter        2′; catheter 700 helps in positioning the endovascular procedure        catheter    -   a one way valve 25 inside the catheter which limits blood loss        during the procedure    -   temporary one way valve 26    -   a selectively permeable, filtering membrane 3′    -   an endovascular mounting ring 900 onto which temporary valve 26        and/or selectively permeable, filtering membrane 3′ are mounted    -   a stent system 950-958 (FIGS. 6-7D) which deploys the mounting        ring 900, temporary endovascular one-way valve 26, and        selectively permeable filtering    -   membrane 3′ by interacting with guiding catheter 700 and        endovascular procedure catheter 2′    -   several holes 600 in the wall of the distal end of the catheter        which may augment antegrade flow of blood during the procedure.

The aforementioned components may be used alone or in combination duringendovascular procedures.

The lumen of endovascular procedure catheter 2′ functions as a workingport allowing for the passage of devices such as imaging devices, tissueresecting devices, or any other device necessary to perform endovascularprocedures on the endovascular vessels or valves.

Endovascular procedure catheter 2′ itself has a one-way valve 25 in itslumen (indicated in phantom) to minimize the loss of fluid, i.e. blood,during the procedure. This one-way valve can be of any configuration aslong as it serves to permit the passage and removal of instrumentsthrough the lumen of the endovascular procedure catheter and inhibitsretrograde blood flow through the endovascular procedure catheter. It islocated proximal to side holes 600 of endovascular procedure catheter2′.

Temporary valve 26 is made of a flexible, durable, non-thrombogenicmaterial. Valve 26 can be any type of one-way valve and consist of asmany or few leaflets as desired as long as it permits the antegrade flowof blood and prevents the retrograde flow of blood. This minimizes thedevelopment of aortic insufficiency created during manipulation of thevalve and minimizes the need for cardiac or cardiopulmonary bypass.Valve 26 depicted in FIGS. 3A, 3B and FIGS. 4A, 4B is a bileaflet valvemounted on mounting ring 900. It permits antegrade blood flow throughfilter 3′ in the open position and inhibits retrograde blood flow bycollapsing against filter 3′ in the closed position. The valve mechanismis a simple one way, single orifice valve which is mounted on thestabilizer. However, the valve can sit independent of mounting ring 900and as aforementioned can take on any shape as long as it functions as aone way valve.

The center of selectively permeable filtering membrane 3′ is mounted onthe outside wall of endovascular procedure catheter 2′. The relativelylarge diameter peripheral edge is mounted on mounting ring 900. It isconical in shape when deployed and sits just upstream of temporary valve26. Filter membrane 3′ is made of a flexible, durable, non-thrombogenicmaterial that has pores that are sized to permit select fluids through(i.e. blood and blood components) but prevents the flow or embolizationof debris generated during the endovascular procedure. By placing itupstream of temporary valve 26 it prevents prolapse of the temporaryvalve leaflets.

In order to assist in positioning and removal of endovascular procedurecatheter 2′, a tapered guiding catheter 700 of the size of the internaldiameter of endovascular procedure catheter 2′ is placed insideendovascular procedure catheter 2′ as depicted in FIG. 3A. In apreferred form, the tapered end at the distal tip DT extendsapproximately 2 centimeters beyond the distal end of endovascularprocedure catheter 2′, but other extension lengths may be used. Guidingcatheter 700 is made of flexible material and the end is soft to preventinjury to the vessels during placement of endovascular procedurecatheter 2′. Guiding catheter 700 has a lumen of such a size as topermit its passage over guide wire 800.

Guiding catheter 700 also serves to deploy and retract mounting ring900, temporary valve 26, and filter membrane 3′. FIG. 6 illustrates anexemplary deployment assembly DA for membrane 3′. That assembly DAincludes elements 950-958, described in detail below. As depicted inFIG. 7A, guiding catheter 700 has slots distally which engage extensionarms 955 of struts 952 that support mounting ring 900.

Mounting ring 900 is mounted on the outside of endovascular procedurecatheter 2′ by struts 952. Mounting ring 900 is comprised of a flexible,durable, nonthrombogenic material which abuts the inner lumen of thevessel when deployed. Temporary valve 26 and/or selectively permeablemembrane 3′ are mounted on mounting ring 900. When mounting ring 900 isdeployed so are the mounted components. Mounting ring 900 is deployed ina controlled, adjustable way. Struts 952 are connected to mobile ring953 and fixed ring 950 which is mounted on endovascular, procedurecatheter 2′ as shown in FIG. 6. Mobile ring 953 has extensions 955 whichextend into the lumen of endovascular procedure catheter 2′ by passingthrough slots in the wall of endovascular procedure catheter 2′. Theseextensions are engaged by grooves 957 in the wall of guiding catheter700. Thus as guiding catheter 700 is withdrawn or advanced insideendovascular procedure catheter 2′, mounting ring 900 is deployed orretracted in an umbrella-like manner. Once mounting ring 900 is deployedto the desired diameter, it is “locked” into place by engaging extensionarms 955 into locking slots 958 cut into the wall of endovascularprocedure catheter 2′. At this point, guiding catheter 700 is disengagedfrom extension arms 955 and removed while mounting ring 900 remainsdeployed.

As shown in FIG. 6, the strut mechanism consists of struts 952, rings950 and 953, and hinges 954. The strut mechanism depicted here consistsof three struts 952 that connect mounting ring 900 to the fixed proximalring 950 that is mounted on the outside of procedure catheter 2′. Thesestruts are also connected to support arms 951 which extend to mobiledistal ring 953 also mounted to the outside of endovascular procedurecatheter 2′. Distal ring 953 has extension arms 955 which extend throughthe slots in the wall of procedure catheter 2′ as shown in FIG. 7.Mounting ring 900 is expanded by moving support rings 953 and 950relative to each other. Struts 952 and arms 951 are hinged at pivotpoints 954.

FIGS. 8A and 8B illustrate another embodiment of a combined valve andfilter device for use in intravascular procedures. The filter means ofdevice 40 is the same as device 10 depicted in FIGS. 1A-1E. A temporaryvalve, depicted in FIGS. 8A and 8B as expandable balloon 25, is situatedon the exterior of outer cannula 1′ of the device. A continuous lumen(not shown) extends from the interior of balloon 35 to port 21′. Port21′ is connected to balloon pump 8 by tube 24. FIG. 8A depicts a device40 with filter 3 deployed and balloon 35 deflated during the systolicphase of the cardiac rhythm. FIG. 8B shows balloon 35 in an inflatedstate 35′ during the diastolic phase. Similar to device 10 of FIG. 3,inner cannula 2 may have a lumen through which instruments can be passedto effect an intravascular procedure. In these figures, the filter isshown to the left of the valve. In other embodiments, this relationshipmay be reversed.

FIGS. 9A and 9B show yet another embodiment of a combined valve andfilter device for use in intravascular procedures. Device 50 is the sameas device 10 in FIGS. 1A-1E with the addition of valve means 26 thatcovers the surface of expanded filter 3. In this embodiment, valve means26 consists of one or a number of thin sheets of material that areattached to the exterior of the base of the cone formed by the expandedmesh filter 3. The sheet material is relatively free to move at the apexof the cone such that mesh filter 3 and the sheet material act inconcert as a flap valve. As shown in FIG. 9B, blood flows through filter3 from the interior of the cone causing flap valve 26 to open and allowflow. As shown in FIG. 9A, blood moving toward the exterior of the conecauses the sheet material of flap valve 26 to move against the exteriorof the cone, preventing flow through filter 3. The device can bedelivered with mesh filter 3 and flap valve 26 in a compressed statewithin outer cannula 1 similar to FIG. 3B. Mesh filter 3 and valve 26then expand once outer cannula 1 is retracted. The sheet material canadditionally be affixed to a more proximal segment of inner cannula 2 bythin filaments 27 or the like to aid in returning valve 26 and filter 3to a collapsed state by advancing the outer cannula 1.

FIGS. 10A and 10B show another embodiment of a combined valve and filterdevice. Device 60 is the same as device 10 in FIGS. 1A-1E with theaddition of valve 28 that covers the surface of expanded filter 3. Valve28 consists of a singular sheet of material that covers the entirety ofthe outer surface of the cone portion of expanded mesh filter 3. It isattached, at a minimum, to the cone's base and either its apex or theexterior of inner cannula 2 near the apex. Slit 29 is cut through thesheet between these attachment sites. As shown in FIG. 10A, slit 29closes against filter 3′ during retrograde flow, i.e. flow from thecone's apex toward its base, preventing the passage of blood throughexpanded filter 3. As shown in FIG. 1 OB, slit 29 moves to an open state29′ during antegrade flow, i.e. from the cone's base toward its apex,allowing passage of blood through expanded filter 3. Slit 29 is shown inthese figures as being in a plane that passes through the long axis ofinner cannula 2, however other orientations are possible. A singularslit is shown, although there could be multiple slits. The sheetmaterial comprising valve 28 can be attached at additional sites alongmesh filter 3 to assist in its function.

FIGS. 11A and 11B depict a combined valve and filter device 30. Thefilter means of device 30 is the same as filter device 20 shown in FIGS.2A-2C. In this embodiment, valve 38 is placed around the exterior ofcannula 17, covering filter 18. Valve means 38 is preferably a flexiblesleeve of material such as silicone rubber. A slit 23 has been cutthrough the sleeve along its length. Slit 23 is normally closed, butopens under positive pressure within cannula 17. Hence, when this deviceis placed in the arterial system with the distal end (near balloon 19)pointed proximally, slit 23 opens during the systolic phase of cardiacrhythm, allowing blood flow through filter 18, and closes during thediastolic phase, preventing blood flow through filter 18. FIG. 11Adepicts valve 38 in a closed position. FIG. 11B depicts valve means 38in an open position. Similar to device 20, device 30 may be configuredwith additional flow paths (not shown) passing through balloon 19. Theseflow paths may have filters associated with them that act to filterblood passing therethrough. These flow paths may include additionalvalves that resist retrograde flow while allowing antegrade flow.

Each of the preceding filter and valve embodiments are adapted to beinserted into a vessel through an insertion site and expanded radiallyfrom the center of the vessel at a site remote from that insertion site.

FIGS. 12-14 disclose a temporary valve assembly (with optional filter)100 which can be inserted substantially perpendicular to the long axisof the vessel and expanded at or near the insertion site.

In a preferred form, the valve assembly 100 consists of fourcomponents—a cannula, a deformable loop, a backing element and a valve.In use, the distal end of the cannula is inserted into a vessel, thedeformable loop is then advanced out of the distal end into the vesseland expanded to abut the interior wall of the vessel. The backingelement spans the interior lumen of the expanded loop and is attached tothe loop at least one point. The backing element is permeable to bloodflow. A valve is affixed to either the expanded loop, the backingelement, or both and functions to stop flow along the long axis of thevessel in a first direction through the loop by collapsing against thebacking element and covering substantially all of the lumen formed bythe loop. The valve further allows flow in a second, opposite directionby deflecting away from the backing element during flow through the loopin that direction.

FIG. 12 depicts the detailed construction of the valve device 100 inexploded form. Button 101 is a rigid piece with an opening that is usedto attach it to a central rod 106. Rod 106 is rigid and is attachable tothe valve components of the device (Parts G, A, and B, as illustrated)as well as two small discs 108 and 108′. Secondary button 102 is affixedto valve holder 107 through tube 103. Parts I form proximal seal 104 andare affixed to each other and delivery cannula 105. Tube 103 can slidethrough the lumens of proximal seal 104 and delivery cannula 105. Rod106 can in turn be passed through the lumens of valve holder 107, tube103, and secondary button 102. Proximal seal 104 includes an o-ring thatseals around the exterior of tube 103. Flexible loop 109 has a holethrough the center of its length seen at the base of the loop formed inthe figure. A backing element 110 and valve 111 are affixed to flexibleloop 109 with any suitable fixation means. Backing element 110 spans theinterior of flexible loop 109. Element 110 is made of flexible materialand in its preferred embodiment is a woven nylon sheet. This sheet canact to filter particulate debris from blood passing through flexibleloop 109. Valve 111 is a set of valve leaflets. In this figure there aresix valve leaflets. These leaflets are attached to the periphery ofbacking means 110, flexible loop 109 or both, for example, by way of aring of material surrounding the leaflets. Once assembled, backingelement 110, valve 111, and flexible loop 109 are affixed to valveholder 107 through the two small through-holes in valve holder 107.These through holes act as hinge points about which the ends of flexibleloop 109 can pivot. Rod 106 is inserted through a central lumen in valveholder 107, superior disc 108, the hole in flexible loop 109, andfinally inferior disc 108′. Discs 108 and 108′ are affixed to rod 106 toimmobilize the center section of flexible loop 109 relative to the lowerend of rod 106. Valve holder 107 fits within the lumen of deliverycannula 105.

In a preferred embodiment of this valve assembly 100, backing element110 is a porous sheet of material that further acts to filter bloodpassing through deformable loop 109. This porous sheet can be a wovenmaterial with an open area that allows the passage of blood, althoughother forms may be used, all within the scope of the invention.

In another preferred implementation of the device 100, deformable loop109 is made from a strip of material with a non-circular cross section.It may have a rectangular cross-section. The thicker side of therectangle can be positioned against the wall of the vessel. This givesthe loop greater flexibility to conform easily to the shape of the walland greater stiffness against flopping or twisting away from the vesselwall under the pressure of blood flowing through the vessel.

The valve 111 is preferably effected by a set of valve leaflets asshown. The valve leaflets can collapse, in an overlapping manner,against backing element 110 to prevent flow in a first direction throughthe loop 100. The leaflets may alternatively coapt against each other soas to prevent flow in the first direction. In the latter form, thedevice may be used without a filter (backing element), to provide avalve-only device. Generally, such a device would be used with a filterin another location.

The leaflets of valve 111 are preferably formed from thin, flexiblesheets of material. There may be any number of leaflets. The leafletsmay be sized to act in concert to close the flow path formed by theloop. The leaflets may alternatively be oversized, such that fewer thanall of the leaflets are required to close the flow path.

In one embodiment, there may be two or more leaflets with one or somecombination of the leaflets capable of closing the flow path through theloop against flow in the second direction.

The valve 111 may alternatively be a sheet of material cut with slits.The slits stay substantially closed (not parted) to prevent flow in afirst direction through the flow path created by the loop 109 bycollapsing against the backing element. The slits allow the Passage ofblood in the second, opposite direction through the flow path by partingopen in the direction away from the backing element.

In a preferred method of using a valve of the form of FIGS. 12-14, thedevice is expanded from a point or set of points on the circumference ofthe vessel into which it is placed until the valve occupiessubstantially all of the cross sectional flow area of that vessel.

Another method of using that device of the form of FIGS. 12-14, is toinsert the distal end of the device into the vessel through an entrysite and expanding the valve proximate to the entry site. This allowsthe device to be placed easily, near the heart, during an open-chestprocedure.

Another method of using the device is to insert its distal end into avessel along a path that is substantially perpendicular to the long axisof the vessel and expand the valve about that path. In a preferredapplication of this method, the device is expanded until it occupies theentire flow path of the vessel and sits within a cross-section of thatvessel taken perpendicular to the vessel's long axis. This minimizes thelength of the vessel taken up by the temporary valve device.

FIG. 15 depicts temporary valve assembly 100, with its valve deployed inaorta 215. In this figure, a procedure is indicated as being performedon aortic valve 212 through a separate access cannula 201 usingprocedure instrument 205. Device 100 is shown with its valve open (as inFIG. 13C) allowing flow through flexible loop 109. This figure depictsthe systolic phase of cardiac rhythm.

In FIG. 16, valve assembly 100 is similarly positioned, but is closed(as in FIG. 13D′), preventing flow back toward the heart. This figuredepicts the diastolic phase of cardiac rhythm. The position of valveassembly 100 distal to the three branches from the aortic arch is shownas a representative application of the device and by no means limits itsapplication to this position.

Preferred Embodiment-Prosthetic Valve

Another aspect of the present invention is a valve fixation device,illustrated in FIGS. 17A-17E. The valve fixation 90 is used to secure aprosthetic valve to the wall of a vessel. In a preferred embodiment, theprosthetic valve is a stentless tissue valve. The tissue valve has abase, located proximal to the heart when placed in an anatomic position,and an apex located distal to the base. The prosthetic valve preferablyhas three commissures and three leaflets. The apex of the commissures istoward the apex of the valve. The valve has an interior surface and anexterior surface. The interior surface serves as an attachment site forthe valve leaflets to the valve anulus. The exterior of the valve isgenerally smooth and forms at least a portion of a cylinder. The valvehas a long axis that runs along the long axis of the cylinder.

The valve fixation device consists of at least one substantially rigidstrut and at least two expandable fixation rings. The strut (s) runsalong the exterior surface of the valve in a direction substantiallyparallel to the long axis of the valve. The rings are preferably locatedabout the circumference of the base and apex of the valve. These ringsare affixed to the strut (s) such that the distance along the long axisof the valve between the rings is fixed. The rings may be located eitheron the interior or exterior surface of the valve. The valve ispreferably affixed to both the rings and the struts by any suitablefixation means including, but not limited to barbs, sutures, staples,adhesives, or the like. In a preferred embodiment, the valve fixationdevice 90 has three struts 92 and two rings 91. Each of the three struts92 is affixed to the valve along an axis that is parallel to the longaxis of the valve and passes proximate to one of the valve commissures.

The rings 91 are preferably self-expanding. Alternatively, rings 91 maybe plastically expandable by any suitable means, such as a balloon. Therings 91 and/or strut(s) 92 may employ barbs or spikes 83 at anylocation along their exterior to aid in securing the valve to the vesselwall. The rings 91 may further be affixed to the exterior of the valveand employ a sealing material 84 or other means, on rings 91, to aid insealing rings 91 against the vessel wall.

In the preferred embodiment, the valve fixation device 90 and attachedtissue valve 80 are inserted in a compressed state into the vascularsystem. The compressed valve/fixation system is then advanced to thesite of implantation, expanded, and secured to the vessel wall. Whenused as an aortic valve replacement, the compressed valve/fixationsystem can be inserted through any peripheral artery distal to theaorta. Alternatively, the valve can be inserted through the wall of acardiac chamber or directly into the aorta itself. Various devices canbe employed to aid in delivering the valve to the implantation site,including, but not limited to delivery cannulae, catheters, and any of avariety of valve holders known in the art.

FIG. 17A depicts a stentless tissue valve 80 such as those known in theart. The valve consists of valve wall 81 and three attached leaflets 82.Valve wall 81 has three sections of its cylindrical form removed so asnot to block branch vessels such as the coronaries. There are manyvariations of this type of valve prosthesis. Any flexible valve with awall and leaflets can be used with the present invention.

FIG. 17B depicts valve fixation device 90 of the present invention. Thisembodiment comprises two expandable ring-like structures 91, shown intheir expanded state, and three struts 92. Struts 92 are relativelyrigid and do not change dimensions from the compressed to the expandedstate of the device 90. The three struts 92 are separated by roughly 120degrees in the illustrated form, as shown in the axial view of thefigure, corresponding to the three commissures of the prosthetic valve.Struts 92 are preferably relatively rigidly attached to expandable rings91 such that the two expandable rings 91 may not rotate about theircentral axes relative to each other. This avoids twisting of tissuevalve 80 during deployment, minimizing the risk of valve leakage.

FIG. 17C depicts valve fixation device 90 affixed to tissue valve 80,forming valve assembly 85. Fixation device 90 can be affixed to tissuevalve 80 at sites along struts 92, expandable rings 91, or both. In thisembodiment, struts 92 and expandable rings 91 are affixed to the outsideof the valve wall 81.

FIG. 17D depicts the assembly 85 of FIG. 17C in a compressed state 85′suitable for insertion into an artery or vein through a relative smalleropening.

FIG. 17E depicts another embodiment of the valve fixation device 90. Inembodiment 86, barbs 83 reside on the exterior surfaces of both struts92 and expandable rings 91 to aid in securing the device 90 to a vesselwall. Felt 84 has also been added to the expandable rings 91 to aid insealing against peri-valvular leaks. Felt 84 could be added to struts92. Other forms of sealant may be used as well.

Preferred Embodiments-Procedure Methods

The above embodiments may be used alone or in combination with otherdevices to carry out procedures on a cardiac valve while the heart isbeating. Below are numerous such procedure methods in accordance withthe invention, which are described to clarify the breadth of possibleapplications of these preferred device embodiments.

FIG. 18 depicts a procedure being carried out on aortic valve 412 whilethe heart is beating. Instrument 405 is manipulating aortic valve 412following the placement of both temporary valve 406 and filter device403. In this embodiment, temporary valve 406 and filter device 403 (forexample device 10 of FIGS. 1A-1F) are separate instruments that havebeen inserted directly into the aorta through separate insertion sites414 and 413. Alternatively, valve 406 and filter 403 may be effected ina single instrument placed through a single incision. Valve 406 andfilter 403 may also be inserted from a peripheral vessel and advanced toa location within the aorta.

Mesh filter 403 is deployed through outer cannula 401 to a preferredsite proximal to the brachiocephalic artery 411. In this position,filter 403 prevents distal embolization of debris that may be dislodgedduring manipulation of valve 412. Portions of inner and outer cannulae401 and 402 and instrument 405 extend to the exterior of the aorta wherethey can be manipulated by a surgeon. In the method illustrated by FIG.18, balloon valve 406 is deployed in the descending aorta 415. Balloon406 is inflated and deflated by an attached balloon pump 408 exterior tothe patient. Balloon pump 408 is in fluid connection with balloon 406through tube 407. Balloon pump 408 is timed to the cardiac rhythm sothat it inflates balloon 406 during substantially all of the diastolicphase and deflates balloon 406 during substantially all of the systolicphase. This allows the valve 406 to perform the function of aortic valve412 while the aortic valve is manipulated.

FIGS. 19, 20, and 21 show another form of the present invention. Thosefigures depict sequential views of method of removing the native aorticvalve and replacing it with a permanent prosthetic valve while the heartis beating. In FIG. 19, balloon valve 406 has been placed in thedescending aorta 415. Cannula 401 has been placed into the aorta toallow the passage of instrument 405. Cannula 401 may have a valve (notshown) along its interior that acts to prevent the flow of blood throughthe cannula while allowing the passage of various instruments.Instrument 405 has been inserted through cannula 401 to remove nativeaortic valve 412. FIG. 20 shows the embodiment described in FIG. 19after substantially all of the aortic valve has been removed. Portions412′ of the aortic valve may remain without deviating from the scope ofthis invention. Indeed resection of native valve 412 can be limited toremoval of those portions of the right and left valve leaflets thatwould cover coronary arteries 409 if the valve were to be compressedagainst the inner walls of the aorta. Instrument 405 has been withdrawnfrom outer cannula 401 to allow the insertion of valve prosthesis 416into the aorta. In this figure, temporary valve 406 is performing thefull function of the resected aortic valve. FIG. 21 shows valveprosthesis 416 expanded against and affixed to the aortic wall at a sitenear the previous attachment of the native valve. Once valve prosthesis416 is in place and functioning, temporary valve 406 can be removed. Nofilter is shown in FIGS. 19, 20, and 21. A filter is not necessary forcompleting the procedure, but could be used without deviating from theintent of the present invention.

Another method of replacing a cardiac valve while the heart is beating,employs described using a combination of the methods disclosed in FIGS.18, 20, and 21. In accordance with the latter method, a set of twoconcentric cannulae, inner cannula 402 that fits within the lumen ofouter cannula 401, are inserted into the vessel. The method furtherinvolves the steps of advancing the set of cannulae to a site downstreamof the cardiac valve, expanding an expandable member 403 from theexterior of the inner cannula 402, performing a procedure at least inpart through the lumen of the inner cannula that removes or disruptscardiac valve 412, retracting inner cannula 402 and expandable member403 through the inner lumen of outer cannula 401 to the site of thecardiac valve anulus, and expanding and affixing prosthetic valve 416 tothe cardiac valve annulus. Using the set of two cannulae allows theinsertion and removal of expandable member 403 on the exterior of innercannula 402 as well as valve prosthesis 416 and other instrumentsthrough the lumen of outer cannula 401 without losing the position ofouter cannula 401 relative to the cardiac valve during the procedure.Expandable member 403 is located anywhere along the length of innercannula 402 and performs any number of functions such as acting as atemporary valve, acting as a filter, or removing or disrupting thecardiac valve leaflets.

FIG. 22 depicts one method of fixing a prosthetic valve 516 to a vesselwall during cardiac rhythm. In this embodiment, prosthetic valve 516 isinserted into aorta 515 in a compressed state through access cannula501. Prosthetic valve 516 is then expanded to abut the inner wall ofaorta 515. A needle 512 and suture 514 are then passed from the outersurface of aorta 515 through the aortic wall and into the prostheticvalve 516. In this depiction, three sutures are used to tack prostheticvalve 516 to the aortic wall in locations superior to the valvecommissures. Alternatively, a fixation means can be passed from theinterior wall of aorta 515 through to the exterior surface. The fixationmeans can be a staple, suture or other suitable means.

In accordance with another aspect of the present invention, a compressedprosthetic valve is inserted into a vessel downstream of the cardiacvalve to be replaced. The prosthetic valve is then expanded to allow itto function temporarily in its downstream location. With that valvetemporarily placed, and functioning, a procedure on the cardiac valve isperformed, involving the disruption and/or removal of the cardiac valve.Then the prosthetic valve is advanced toward the site of the excised ordisrupted cardiac valve, and affixed at a site within the vessel at ornear the site of the excised or disrupted cardiac valve. During theprocedure on the cardiac valve, the expanded prosthetic valve functionsas the native valve, preventing retrograde flow.

The cardiac valve procedure occurring while the prosthetic valve isdownstream of its final position, may be performed through an incisionsomewhere between the cardiac valve and the prosthetic valve.Alternatively, the procedure could be done with tools inserted throughthe functioning prosthetic.

FIGS. 23A and 23B depict a method for repairing a stenotic aortic valvein accordance with the invention. FIG. 23A shows stenotic aortic valve612 within the aortic root. View 1 in this figure shows two views ofstenotic valve 612 looking along the long axis of aorta 615 proximal tothe valve. In this view, the leaflets of valve 612 provide a reducedaperture due to the stenosis.

FIG. 23B shows the aortic valve after the repair method of the inventionhas been implemented. Initially, the aortic valve 612″ is disrupted byincising each leaflet such that six leaflets are formed. A balloonvalvuloplasty may optionally be performed on valve 612″. Following thedisruption of valve 612″, a valve support 620 is positioned upstream ofthe valve 612″. Preferably, the valve support 620 includes an expandableouter ring (circular or otherwise, e.g. elliptical, oval, polygonal),which is spanned by a bloodflow permeable structure. The outer ring isexpanded to be proximal to and affixed to the aortic wall, so that thesupport structure provides a surface against which the disruptedleaflets can collapse, forming a multileafed flap valve, similar to thevalve described above in conjunction with FIGS. 12-14.

FIG. 24 depicts a procedure being performed on the aortic valve 412while the heart is beating. Instrument 405 is manipulating aortic valve412 following the placement of both temporary valve 100 and filterdevice 410 (for example, device 10 of FIG. 1F). In this embodiment,temporary valve 100 and filter device 410 have been inserted directlyinto the aorta through separate insertion sites 414 and 413.

Mesh filter (not visible) has been deployed through outer cannula 401 toa site proximal to the coronary arteries 409. Filter material 71 coversthe mesh filter. Filter extensions 70 extend from the filter materialand form filter leaflets that prevent embolic material from entering thecoronary arteries 409. Portions of the inner and outer cannulae 401 and402 and instruments 405 extend to the exterior of the aorta where theycan be manipulated by the surgeon.

In the method illustrated in FIG. 24, temporary valve 100 is deployed inthe descending aorta 415, and as described earlier, expands to occupythe entire flow path. Temporary valve 100 is shown in the systolic phaseof cardiac rhythm, i.e. with its valve open (as in FIG. 13D′), allowingflow through the device.

In other embodiments of the invention the temporary valve and/or filtermay be deployed downstream of the aortic valve, or in still other forms,downstream of the mitral or other cardiac valves. Further, these devicesmay be deployed downstream of one cardiac valve while procedures arebeing performed on another cardiac valve upstream of the devices.

Preferred Embodiment-Valved Arch Filter

In accordance with a further feature of the invention, there is provideda novel valved arch filter device 1000 (FIG. 25) which provides atemporary one-way valve between the coronary ostia (where the coronariescome off the aorta) and the origin of the great vessels (i.e., thosegoing to the arms and brain).

The temporary one-way valve performs the function of the native aorticvalve during the brief period after the native diseased valve has beenremoved and before a prosthetic valve has been implanted. Ideally, thistemporary valve would sit in exactly the same position as the naturalvalve, but this area needs to be kept free for fixation of theprosthesis. Therefore, the temporary valve is located downstream fromthe natural aortic valve. In this position, the left ventricle is sparedthe hemodynamic stress of acute severe aortic insufficiency. That is tosay, if one simply removed the aortic valve on a beating, unassistedheart without deploying a temporary valve, after each heart beat, themajority of the previously-ejected blood from that heart beat would backup into the heart. As a result, the left ventricle, the main pumpingchamber, would stretch out and fail, and forward blood flow to the bodywould be compromised. However, the temporary valve, in the positiondescribed above, would keep the blood from backing up betweenheartbeats.

In addition, because the valve would be proximal to the vessels to thebrain and other organs, blood pressure and flow to these organs would berelatively unaffected between heartbeats, as forward flow and diastolicpressure would be preserved. The only potentially adverse physiologiceffect of having a temporary valve in that position is that thecoronaries, which naturally originate above the native aortic valve, sitbelow the temporary valve. As such, coronary flow would have to occurduring systole (while the heart is beating) instead of during diastole(between heartbeats) when it usually occurs. It has been demonstrated,in animals, that this is well tolerated for short periods of time underanesthesia, and should not present a problem.

The new valved arch filter device 1000 further provides downstreamfiltration. That is to say, to prevent small pieces of tissue, oremboli, that break off during removal of the native valve and/orimplantation of the prosthetic valve from flowing downstream where theycould potentially become lodged in small branches of the arterial treeand cause injury to the brain, liver, kidneys, or other vital organs.

Several embodiments of temporary valves with integral filters have beenconceived and described in earlier patent applications, such as thoseidentified above. This new valved arch filter embodiment has variouscharacteristics. For one thing, the new device 1000 is intended to bepassed percutaneously and positioned under transesophageal echo orfluoroscopy. Secondly, the new device has a central working channel thatallows catheters needed for handing off the debridement tool or theprosthesis and fixation device to be inserted percutaneously. Thirdly,the new device has radial symmetry, so radial orientation is notimportant. Fourthly, the present device is intended to cover the entirearch (i.e., that section of aorta from which the vessels to the brainarise) so the positioning of the device would have high tolerances.Still other ways of characterizing the present invention will beapparent from this description and the associated figures.

The valve design incorporated in the preferred construction of the newvalved arch filter 1000 is unique. The valve includes a thin-walledmembrane 1002 shaped like a parabolic cone. The cone shaped membrane1002 is tethered at the apex by a catheter 1004 that extends coaxiallydown the center of the valve-filter assembly 1000. The cone shapedmembrane 1002 is tethered at the base at 3-4 discrete points (A, B, Cand D in FIGS. 29 and 35) around its circumference to the inside of athin plastic valve seating retaining ring 1006 that, though collapsible,expands to the internal circumference of the aorta.

When blood attempts to pass by the valve in a retrograde fashion betweenheartbeats, the membrane 1002 inflates (FIGS. 25 and 30), compressingits lower ¼th against the inner surface of the thin plastic ring 1006.The ring 1006 is compressed against the inner surface of the aorta,resulting in isolation of the proximal aorta from the pressurized distalaorta, and preventing reversal of flow during diastole.

With the onset of systole, the pressure in the proximal aorta rapidlyrises. As soon as the proximal aortic pressure exceeds distal aorticpressure, the parabolic membrane 1002 is compressed down around thecentral catheter 1004 (FIGS. 33-35), allowing unhindered flow of bloodin the antegrade direction.

The central catheter 1004 is held in the middle of a filter tube 1008 bycollapsible radial struts 1010 (FIGS. 26, 29, 31-34) at the two ends ofthe valve filter assembly 1000. The struts 1010 allow traction to beapplied to the catheter 1004 extending through the central lumen 1012,as may be necessary in valve debridement, hand-off, and insertion,without the catheter 1004 rubbing against the inner surface of theaorta.

The filter membrane 1002 is fabricated of extremely lightweight filtermaterial fashioned into tube 1008, mounted on a lightweightself-expanding internal skeleton (1014 (FIGS. 27 and 28) of nitinol orother superelastic or otherwise satisfactory material. This allows theentire assembly 1000 to compress circumferentially to allow insertionthrough a reasonably small catheter. When a sheath is backed off of theassembly, the superelastic skeleton expands the filter tube 1008 andvalve assembly 1000, thereby allowing it to conform to the section ofaorta. The sheath can, at a later time, be advanced to re-compress thefilter valve assembly so as to allow for removal.

The central catheter 1004 can be the size of the catheter in aconventional intra-aortic balloon pump (IABP); and the filter and valveassembly is not substantially bulkier than the material of which theIABP balloon is made. The construction, although somewhat more complexthan a simple balloon, can be made of very lightweight materials, as thephysical demands on it are considerably less than those required by anIABP.

The valved arch filter assembly 1000 is provided in several sizes toaccommodate the various sizes of aortas generally encountered. Thetolerance with respect to circumferential size is relatively large, asthe valved arch filter assembly is intentionally oversized to ensureintimate apposition of the filter tube and the aorta. As the elasticskeleton is delicate, the forces on the inner surface of the aorta aresmall.

The length of the device can be patient-specific; however, thetolerances in this regard are quite high. The ascending aorta generallymeasures 10 centimeters or more, and the descending aorta, 25centimeters or more. As long as the valved end of the assembly isdisposed somewhere in the ascending aorta, proximal to the greatvessels, and the distal end of the assembly is disposed in thedescending aorta, all emboli bypass the brain, and the temporary valvefunctions as intended.

In a preferred embodiment, the filter tube 1008 is closed as a blindsack of filter material distally. With this configuration, the back endof the valve filter assembly does not have to extend all the way intothe descending aorta, but can instead terminate in the distal ascendingaorta, the mid-arch aorta, or beyond. An advantage of a longer filtertube is that it ensures proper coaxial orientation. An open tube designwould only divert embolic material away from the brain, but emboli tothe kidneys, liver, intestines, and legs could still occur. A blindsack, on the other hand, as disclosed herein, captures embolic materialand allows it to be removed with the catheter.

The lumen of the central catheter 1004 allows a variety of catheters tobe passed to the area of the native diseased aortic valve, or across thevalve into the left ventricular cavity for intra-cardiac hand-off ofdebridement tools, valve prostheses, or fixation devices. In otheriterations, the debridement tools, prostheses, and fixation mechanismscan be designed to function down through the central lumen.

Although preferred and other embodiments of the invention are describedherein, further embodiments may be perceived by those skilled in the artwithout departing from the scope of the claims.

What is claimed is:
 1. A method for enabling performance of an operationon a cardiac valve of a heart while the heart is beating, the methodcomprising: providing a valved filter device comprising a valve, afilter and a circumferential outer edge; placing the valved filterdevice in a flow path of a blood vessel downstream from the cardiacvalve while the heart is beating; moving the valved filter device to adeployed configuration where the outer edge of the valve contacts aninterior wall of the vessel such that the valve is operative to effectgreater antegrade flow than retrograde flow through the vessel when thevalved filter device is in the deployed configuration while maintainingcontact between the outer edge and the interior wall of the vessel, andthe filter is operative to restrict the passage of emboli while allowingblood to flow through the vessel.
 2. The method of claim 1, wherein thevalve of the device is configured to allow natural antegrade blood flowduring a systolic phase of cardiac rhythm.
 3. The method of claim 2,wherein the valve of the device is configured to obstruct retrogradeblood flow during a diastolic phase of cardiac rhythm.
 4. A method forperforming an operation on a cardiac valve of a heart while the heart isbeating, the method comprising the steps of: providing a valved filterdevice comprising a valve, a filter and a circumferential outer edge;positioning a valved filter device in a flow path of a blood vesseldownstream from the cardiac valve while the heart is beating; moving thevalved filter device to a deployed configuration where the outer edge ofthe valve contacts an interior wall of the vessel such that the valve isoperative to effect greater antegrade flow than retrograde flow throughthe vessel when the valved filter device is the deployed configurationwhile maintaining contact between the outer edge of the valve and theinterior wall of the vessel; resecting at least a portion of the cardiacvalve while the heart continues to beat; and affixing at least oneprosthetic valve at or downstream from the resected cardiac valve. 5.The method of claim 4, wherein the valve of the device is configured toallow natural antegrade blood flow during a systolic phase of cardiacrhythm.
 6. The method of claim 5, wherein the valve of the device isconfigured to obstruct retrograde blood flow during a diastolic phase ofcardiac rhythm.
 7. A method for enabling performance of an operation ona cardiac valve of a heart while the heart is beating, the methodcomprising: providing a valved filter device comprising a valve, afilter and a circumferential outer edge; placing a valved filter devicein a flow path of a blood vessel of the cardiac valve while the heart isbeating; moving the valved filter device to a deployed configurationwhere the outer edge of the valve contacts an interior wall of thevessel such that the valve is operative to effect greater antegrade flowthan retrograde flow through the vessel when the valved filter device isin the deployed configuration while maintaining contact between theouter edge of the valve and the interior wall of the vessel, and thefilter is operative to restrict the passage of emboli while allowingblood to flow through the vessel.
 8. The method of claim 7, wherein thevalve of the device is configured to allow natural antegrade blood flowduring a systolic phase of cardiac rhythm.
 9. The method of claim 8,wherein the valve of the device is configured to obstruct retrogradeblood flow during a diastolic phase of cardiac rhythm.
 10. A method forperforming an operation on a cardiac valve of a heart while the heart isbeating, the method comprising the steps of: providing a valved filterdevice comprising a valve, a filter and a circumferential outer edge;positioning a valved filter device in a flow path of a blood vesseldownstream from the cardiac valve while the heart is beating; moving thevalved filter device to a deployed configuration where the outer edge ofthe valve contacts an interior wall of the vessel such that the valve isoperative to effect greater antegrade flow than retrograde flow throughthe vessel when the valved filter device is in the deployedconfiguration while maintaining contact between the outer edge of thevalve and the interior wall of the vessel; resecting or disrupting atleast a portion of the cardiac valve while the heart continues to beat;and affixing at least one prosthetic valve at, upstream or downstreamfrom the resected cardiac valve.
 11. The method of claim 10, wherein thevalve of the device is configured to allow natural antegrade blood flowduring a systolic phase of cardiac rhythm and obstruct retrograde bloodflow during a diastolic phase of cardiac rhythm.